U.S. patent number 8,141,414 [Application Number 12/496,753] was granted by the patent office on 2012-03-27 for apparatus for determining the condition of a tire tread of a vehicle wheel.
This patent grant is currently assigned to Snap-On Equipment SRL a Unico Socio. Invention is credited to Francesco Braghiroli.
United States Patent |
8,141,414 |
Braghiroli |
March 27, 2012 |
Apparatus for determining the condition of a tire tread of a
vehicle wheel
Abstract
A method and apparatus for determining the condition of a tire
tread of a vehicle wheel including a rim and a tire configured to
perform the steps of: (1) emitting an electromagnetic radiation
towards the tread of the tire, (2) receiving a reflected
electromagnetic radiation from said tread of the tire in response
to the emitted radiation, (3) processing the reflected radiation to
obtain height data including respective heights of a plurality of
points located on the tread of the tire, (4) repeating the steps
(1) to (3) in successive time intervals within which the vehicle
wheel has driven a predetermined distance, and storing the
respective height data, particularly average values of the height
data, each in dependence of the driven distance, and (5) deriving
from the succession of the stored height data a residual mileage of
the tire.
Inventors: |
Braghiroli; Francesco (Reggio
Emilia, IT) |
Assignee: |
Snap-On Equipment SRL a Unico
Socio (Correggio (RE), IT)
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Family
ID: |
40042979 |
Appl.
No.: |
12/496,753 |
Filed: |
July 2, 2009 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100000310 A1 |
Jan 7, 2010 |
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Foreign Application Priority Data
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Jul 3, 2008 [EP] |
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08012038 |
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Current U.S.
Class: |
73/146;
340/442 |
Current CPC
Class: |
G01M
17/02 (20130101); B60C 11/246 (20130101); G01B
11/22 (20130101) |
Current International
Class: |
G01M
17/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1997870 |
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Jul 2007 |
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CN |
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0 547 365 |
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Jun 1993 |
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EP |
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10-157579 |
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Jun 1998 |
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JP |
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2002-183260 |
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Jun 2002 |
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JP |
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WO 2005/121698 |
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Dec 2005 |
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WO |
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Other References
Chinese Office Action, w/ English translation thereof only, issued
in Chinese Application No. 200910137466.5, dated Oct. 19, 2011.
cited by other.
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Primary Examiner: Caputo; Lisa
Assistant Examiner: Jenkins; Jermaine
Attorney, Agent or Firm: McDermott Will & Emery LLP
Claims
The invention claimed is:
1. A method for determining the condition of a tire tread of a
vehicle wheel including a rim and a tire comprising the steps of:
(1) emitting an electromagnetic radiation towards the tread of the
tire, (2) receiving a reflected electromagnetic radiation from said
tread of the tire in response to the emitted radiation, (3)
processing the reflected radiation to obtain height data including
respective heights of a plurality of points located on the tread of
the tire, (4) repeating the steps (1) to (3) in successive time
intervals within which the vehicle wheel has driven a predetermined
distance, and storing the respective height data, particularly
average values of the height data, each in dependence of the driven
distance, and (5) deriving from the succession of the stored height
data a residual mileage of the tire.
2. The method according to claim 1, characterized in that the
residual mileage is calculated from the current driven distance of
the tire and the stored height data.
3. The method according to claim 1 or 2, characterized in that the
residual mileage is calculated by at least one of the following
steps: curve fitting, interpolation-extrapolation on the base of
the stored data.
4. The method according to claim 1 or 2, characterized in that the
height data are stored in a database, wherein the stored height
data are associated to identification data of the respective
tire.
5. The method according to claim 1 or 2, characterized in that the
height data are further processed to determine any irregular tread
wear pattern.
6. The method according to claim 1 or 2, characterized in that the
height data were obtained in connection with a wheel balancing
operation or a tire changing operation.
7. The method according to claim 1 or 2, characterized in that at
least one circumferential portion of the surface of the tire tread
is scanned by the emitted radiation.
8. The method according to claim 1 or 2, characterized in that the
tire tread is scanned while the vehicle wheel is rotated.
9. The method according to claim 1 or 2, characterized in that the
height data are associated to respective rotary angles and
positions along the width of the tire tread.
10. An apparatus for determining the condition of a tire tread of a
vehicle wheel which includes a rim and a tire, the apparatus
comprising: an emitter source for emitting radiation
electromagnetic towards the tire tread, at least one detector for
receiving radiation reflected from said wheel assembly in response
to the emitted radiation, a data processing device connected to
said emitter source and said at least one detector for processing
data, wherein said data processing device is configured to perform
the steps of: obtaining height data including respective heights of
a plurality of points located on the surface of the wheel assembly
based on the reflected radiation received from the at least one
detector, storing the height data, particularly an average value of
the height data, successively obtained in time intervals within
which the vehicle wheel has driven a predetermined distance; and
deriving from the succession of the stored height data a residual
mileage of the tire.
11. Apparatus according to claim 10, wherein said data processing
device is configured to obtain along at least one circumferential
portion of the tread a height data.
12. Apparatus according to claim 11, wherein said surface profile
covers the complete surface of the tire tread is scanned.
13. Apparatus according to any one of the claims 10 to 12, wherein
said data processing device is adapted for obtaining height
information by scanning the tread surface while said wheel assembly
is rotated by at least one revolution.
14. Apparatus according to any one of the claims 10 to 12, wherein
the emitted electromagnetic radiation is a laser radiation.
15. Apparatus according to any one of the claims 10 to 12, wherein
the emitter source is configured to emit the radiation in form of a
linear beam or in the form of a planar beam.
16. Apparatus according to any one of the claims 10 to 12, adapted
to be implemented into a wheel balancer or into a tire changer.
Description
The present invention relates to a method and an apparatus for
determining the condition of a tire tread of a vehicle wheel
utilizing non-contact data collection and analysis of the collected
data, and more specifically to an apparatus for obtaining data by
non-contact measurement for the determination of the conditions of
the tire.
A non-contact method and a system for analyzing tire conditions by
directing radiation to the tire to be examined and sensing
reflected radiation is, for example, disclosed in document U.S.
Pat. No. 7,269,997 B2.
The object of the invention is to provide a method and an apparatus
of the kind set forth in the opening part of this specification
which provide a prediction of the residual mileage (durability) of
the tire of the vehicle wheel.
According to the invention, the object is solved by the features of
claim 1 or by the features of claim 10.
According to the present invention, an electromagnetic radiation,
especially, light or a laser radiation is emitted towards the tire
tread. At least one detector is provided for receiving radiation
reflected from the tire tread in response to the emitted radiation.
Electrical signals which represent the reflected radiation are fed
to a data processing device, such as a computer for running a
predetermined program, to determine conditions of the tire,
especially its residual durability (lifetime, mileage). The data
processing device obtains geometrical information, such as height
or depth relative to a reference baseline, of a plurality of points
on the wheel assembly based on the signals received from the at
least one detector. The plurality of points may be located on the
tire tread extending between the two sidewalls of the tire.
Non-contact measurement concepts are known from U.S. Pat. No.
5,054,918 and U.S. Pat. No. 7,269,997 and can be used for carrying
out the invention.
More specifically, the geometrical information about the shape of
the surface or of a surface profile of at least a part of the tire
tread is generated based on the height or depth information
obtained by the non-contact measurement concept.
The scanning of the tire tread and the processing of the measured
data to obtain the geometrical information about the tread
condition is repeated in several time intervals, for example at the
regular car check intervals or at regular tire check intervals,
each after the tire has been driven a predetermined distance, for
example 15.000 km. The distance can be shorter or longer, of
course. The results of the measurements at each time interval were
stored in the data processing device or in a separate data base
which can be located in the tire shop or vehicle repair shop or at
another appropriate location. Preferably, the data base is located
at the vehicle repair shop which usually take care of the repair
and maintenance of the automobile on a regular base. The obtained
height or depth data are stored respectively in dependence of the
driven distances.
The residual mileage (lifetime or durability) of the tire can be
calculated from the current mileage (driven distance) of the tire
and from the stored height data. The relationship between the tread
wear and driven distance (mileage) is not linear. The most tires
tend to wear more slowly as long as they are used. By storing the
obtained results, the historical data demonstrating the tire wear
are available for the determination of the tire condition. In order
to identify the tire, respective identification data are stored
together with the associated height data. Especially an RFID-system
can be used to recover the respective data of the tire.
Regarding the determination of the condition of the tire, the
measurement concept may include the measurement of one single
circumferential portion or of several circumferential portions of
the treaded surface of the tire and generating a surface profile
showing respective heights or depths on the surface of the tire.
For example, the surface of the tire can be scanned by rotating the
vehicle wheel for at least one revolution. During the rotation, the
emitter source continuously or intermittently emits radiations onto
the tire tread and the at least one detector continuously or in a
corresponding intermittent manner obtains (receives) reflected
radiations from the tire tread and transmits respective electric
signals to the data processing device. A surface profile showing
the complete circumferential surface can be created by the data
processing device. Further, the data processing device can
calculate an average value of the measured heights or depths. The
average value of the measured heights or depths of the tread
profile along one or more circumferential portions of the tire
tread represent the tread wear and can be stored for the
determination of the residual mileage.
According to a particular aspect of the present invention, the
height/depth information may be shown on a display means.
The present invention can be implemented into a wheel balancer
apparatus or tire changer including a mounting means to which the
vehicle wheel can rotatably mounted on a shaft.
Still other advantages of the invention will become readily
apparent from the following detailed description, simply by way of
illustration of the invention and not limitation. As will be
realized, examples illustrated herein.
The accompanying drawings illustrate exemplary embodiments of the
invention.
FIG. 1 shows an overall view of an exemplary non-contact analytic
system for determining the condition of a tire tread,
FIG. 2 depicts the implementation of the system shown in FIG. 1
into an apparatus having a shaft for a rotary support of the
vehicle wheel, and
FIG. 3 shows the relationship between tread wear and driven
distances (mileage).
FIG. 1 refers to an embodiment of the present invention and show an
exemplary apparatus 10 (non-contact analytic system) for
determining the condition of a vehicle wheel 14, basically
including a tire 34 and a rim 20, by analyzing a tread profile of
the tire 34 including geometrical information, such as height
and/or depth, related to various points on the tread of the tire
34.
FIG. 2 shows a tread surface 35 of the tire 34 of the vehicle wheel
which is mounted rotary on a shaft 18 of an apparatus 16 which can
be a wheel balancer or a tire changer. The tread surface 35
includes tread patterns 36, 38 and 40.
As is shown in FIGS. 1 and 2, the apparatus 10 for detecting the
condition of a vehicle wheel 14 according to the present invention
includes the apparatus 16 with the driven shaft 18 for the vehicle
wheel 14 to be attached thereto, an emitter source 22, such as a
laser which can emit a linear laser beam or a planar laser beam,
LED light, or another appropriate light source, as well as at least
one detector 24 such as cameras, a charged coupled device CCD or
CMOS detectors, and a data processing device 26 such as a computer
for running corresponding software to carry out the data evaluation
of the detection signals of the at least one detector 24.
Electromagnetic radiation is emitted towards the tread surface 25,
such as laser illumination light and electric signals representing
the radiation reflected by the tread surface 35 are produced by at
least one detector 24 which picks-up the reflected radiation and
the electric signals are transmitted to the data processing device
26 for obtaining height data or depth data for the tread profile
along the circumferences of the tire. The shape and/or depth or
tread patterns 36, 38, 40 of the tire 34 and output signals or data
of an image representing the profile can be shown on a display
30.
The heights or depths of the tread profile can be measured along
one circumferential tread portion, especially along a central
circumferential tread portion, or along several circumferential
tread portions.
Preferably, an average value of the measured heights or depths is
calculated by the data processing device 26. The average value
represents the tread wear. The measurements are repeated in given
time intervals or after given driven distances, for example at the
regular vehicle checks in a vehicle repair shop. Each measured
tread wear value is stored and a plot like the one shown in FIG. 3
can be drafted or calculated by the data processing device 26. The
data processing device 26 can include a data base in which the
measured tread wear values are stored. From the plotted trend wear
values the data processing device 26 calculates for example by
curve fitting, intrapolation-extrapolation, the residual
functionality or admitted residual usage (mileage) of the tire. By
an ID-system for example a RFID-System the measured and stored
values can be associated to the tire.
Further, it is possible to associate irregular tread wear patterns
to defects on car components. For example, an one-side wear or
feathering of the tread indicates to defects on the steering system
or on the suspension system.
Based on the high accuracy of the measurement in the range of a
tenth of mm an accurate depth map of the tire tread can be provided
for the diagnosis. An early warning of a potential wearing of the
tire can be achieved as well. When using a linear scanning beam
(laser beam) a dotwise scanning of the tread surface is achieved
along the circumferential portion of the tread surface 35. When
using a planar laser beam the complete width of the tread surface
35 can be scanned during the rotation of the vehicle wheel 14.
* * * * *